What is "processed food"??

Inspired by Scott's post about dinner last night:

Although I should be eating processed foods less (WSJ article) I still can't resist a delicious italian sausage or brat every now and then. 

Sometimes I think that the "processed food" argument is as vague as a food label claiming its product has "no preservatives." Does it have salt? Yes? Then it has at least one preservative. I get that there are a lot of artificial preservatives out there that can generally be bad, but food preservation is practical for reasons which should be all too obvious. (Well, they should be obvious, but in a world populated by meaningless (but probably effective) marketing slogans like "all natural" and "no artificial flavorings," I'm cynical about people's awareness of the food they eat.)

Anyway, back to processed food. Most food has been processed in some way. Whether it's the "fresh" tomatoes in the produce section (that have been ripened with chemicals) or apples coated in wax, or flour that was milled from grains, most of the "whole" ingredients we think of are not free from our industrial food supply. Sausages are processed by combining various cuts of meats and seasoning in a grinder.

So it really comes down to: what level of processing are you willing to accept in the food that you eat? I'm at ease with most old-world processing techniques, like sausage-making. Contrast that with a bag of M&Ms, which start with corn that is macerated in some esoteric manufacturing process, some of whose by-products are then transformed into a syrupy concoction, which is then used by Mars to sweeten their cocoa, which is then coated with more corn syrup and God-knows-what kind of coloring. And along the way, there are various preservatives, stabilizers, and flavorings added as well.

The lines we draw for ourselves are iffy at best, and our rules are regularly broken. I try my best to avoid "processed foods" as well, but I mean it in the sense that I'm going to avoid those M&Ms, and have myself some fresh sausage.